Process of manufacturing photographic papers.



Unrran s'rA'rEs PATENT orrion Specification of Letters Patent.

Patented Feb. 13, 1e06,

Application filed September l6, 1905. Serial No- 278,775-

To all whom it may concern.-

Be it'known that I, IGNAZ HoFFsIiMMER, manufacturer, a subject of theGerman Emperor, residing at 11 Schenkelstrasse, Duren, Rhine Province,Germany, have invented certain new and useful Improvements in Processesof Manufacturing Photogra hic Papers, of which the following is'a specication.

This invention relates to a process of manufacturing photogra hicpapers, and has for its object to render 518 process more expeditiousand considerably cheaper.

As is well known, pa ers which are to be employed for'photograp 'cpurposes may be insulated against the emulsions by a plying certainprotective layers or by specia preparations. Such protectiv'e layers andpreparations may, according to the respective objects, be formed bymeans of starch, agaragar, gelatin, milk, solutions of COllOdlOIl, wool,and other like preparations. The coating with baryta gelatin customarywithmany photogra hic apers'is also such a protectlve ayer, alt oug thephysical property of the paper is also afiected when the last-namedpreparation is used. The coating with baryta gelatin thus serves less asan actual rotective layer than as a means for beautilying it and isintended to smooth and equalize the inequalities of the paper. All theknownprotective la ers and preparations,

however, only partia ly fulfil their object, as

it frequently happens that in spite of these protective layers andpreparations the emulsions penetrate the paper. Therefore for makingsuch photograplhic pa ers only raw paper of ver good qua 'ty cou dhitherto be employed, or which reason such photographic papers arecomparatively expensive.

Now I have ascertained by experiments thatthe penetration of theemulsions into the paper may be perfectly prevented by spreadmg over theraw paper a fibrous protective coveringfor instance, of thin paper,fabric, and the like. This fibrous protective covering is laid onthe'raw aper and combined therewith by means of other suitable manner.This fibrous layer is then emulsioned, after, if necessary, it has beencoated previously with baryta. This improved process for makinghotographic papers has the advantage of al owing a certain latitude asregards cleanliness and com-- position in the selection of the raw paperby the application of a fibrous protective layer or covering, as raw1paper of lower qua ity may be employed, W finished apers isconsiderably reduced.

What I o aim as my invention, and desire to secure by Letters Patent, is

IGNAZ HOFFSUMMER.

fphotographic pa er conbrous material aid over Witnesses:

Y BESSIE F. DUNLAP,

LoUIs VANDORY.

an adhesive or in ereby the price of the

